In a statement issued late Thursday, Hezbollah said, "In a first response to the massacres in Nabatiyeh and Sawaneh, Islamic resistance combatants fired dozens of Katyusha-type rockets at Kiryat Shmona."
According to Press TV, the retaliation came shortly after Hezbollah said Israel would "pay the price" for killing civilians including five children in southern Lebanon, the deadliest day for Lebanese people in four months of Israeli aggression.
Seven of the civilians were killed in Nabatieh late on Wednesday when an Israeli strike on the southern city hit a multi-story building. The dead were from the same extended family, and included three children.
It followed an earlier attack that killed a woman and two children in the village of al-Sawana at the Lebanese border, who were buried on Thursday.
The bodies of the children, wrapped in green shrouds, were so small they each fitted on two plastic chairs as people came to pay respects, Reuters reported. Their father held them tight before they were buried as another man sobbed on his shoulder, it said.
"The enemy will pay the price for these crimes," Hezbollah politician Hassan Fadlallah told Reuters, saying Hezbollah had a "legitimate right to defend its people".
Hezbollah has responded to Israeli aggression in solidarity with the Palestinians with a flurry of rocket fire and precision missiles that have hit military targets.
Hezbollah has said its campaign will stop only when Israel halts its war on the Gaza Strip, where more than 28,000 people have been killed according to health authorities in Gaza.
On Wednesday, Hezbollah targeted a military base in Safed about 15 km from the Lebanese border with rocket fire, killing one soldier and wounding eight others.
Strikes on dense urban areas far from the Lebanese border like those on Nabatieh on Wednesday are a new phase in Israeli aggression.
The United Nations urged a halt to what it called a "dangerous escalation" of the conflict, which has played out in parallel to the Israeli war on Gaza and fueled concerns of a wider confrontation.
Andrea Tenenti, spokesman for UNIFIL, the UN's peacekeeping force in Lebanon, said it had noted a "concerning shift in the exchanges of fire, including targeting of areas far from the Blue Line" - the current demarcation between Lebanon and the territories occupied by Israel.
The Israeli violence has killed more than 200 people in Lebanon. Around a dozen Israeli troops and five other Israelis have been killed in retaliatory strikes by Hezbollah which have also forced Tel Aviv to evacuate settlements near the Lebanese border.
MNA